Position detection circuit and position detection method

ABSTRACT

A position detection circuit and position detection method are provided to enable more flexible position detection even if an object is present above a touch sensor. The position detection circuit is connected to a capacitive touch sensor formed with a plurality of line electrodes that are two-dimensionally arranged. At least one memory device stores processor-readable instructions that, when executed by at least one processor device, cause the position detection circuit to: recognize an electrically conductive object located above a touch sensor based on two-dimensional data indicating detection values regarding capacitance, and detect a touch position or touch area on the touch sensor based on the two-dimensional data using different touch detection conditions for an outside and an inside of an area where the object is present.

BACKGROUND Technical Field

The present disclosure relates to a position detection circuit and aposition detection method.

Background Art

Patent Document 1 (Japanese Patent Laid-open No. 2012-088899) disclosesa touch panel apparatus. If an object contacting a mutual capacitancecapacitive touch panel is determined as a water drop, the touch panelapparatus invalidates output of coordinate values corresponding to thewater drop in order to prevent operation errors.

However, the apparatus disclosed in Patent Document 1 (Japanese PatentLaid-open No. 2012-088899) has a problem that it does not allow flexibleposition detection. For example, if a finger is moved while a coin ispressed against the touch surface, this motion of the finger is notdetected as a series of touch manipulation.

BRIEF SUMMARY

An object of the present disclosure is to provide a position detectioncircuit and position detection method that enables performance of moreflexible position detection even if a foreign object is present above atouch sensor.

A position detection circuit according to a first aspect of the presentdisclosure is a circuit connected to a capacitive touch sensor formedwith a plurality of line electrodes that are two-dimensionally arrangedThe position detection circuit includes at least one processor device;and at least one memory device storing processor-readable instructionsthat, when executed by the at least one processor device, cause theposition detecting circuit to: acquire two-dimensional data indicating adistribution of detection values regarding capacitance on the touchsensor; recognize an electrically conductive object located above thetouch sensor based on the acquired two-dimensional data; and detect atouch position or touch area on the touch sensor based on thetwo-dimensional data using different touch detection conditions for anoutside and an inside of an area where the recognized object is present.

A position detection method according to a second aspect of the presentdisclosure is a position detection method using a capacitive touchsensor formed with a plurality of line electrodes that aretwo-dimensionally arranged. The method is performed by one or moreprocessors and includes: acquiring two-dimensional data indicating adistribution of detection values regarding capacitance on the touchsensor; recognizing an electrically conductive foreign object locatedabove the touch sensor based on the acquired two-dimensional data; anddetecting a touch position or touch area on the touch sensor based onthe two-dimensional data using different touch detection conditions foran outside and an inside of an area where the recognized object ispresent.

The present disclosure allows more flexible position detection even ifan object is present above a touch sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram of an electronic device into which aposition detection circuit according to one embodiment of the presentdisclosure is incorporated;

FIG. 2A and FIG. 2B are schematic diagrams depicting functionalrequirements of the position detection circuit in FIG. 1;

FIG. 3A and FIG. 3B are figures depicting distributions of signal levelsin a state in which a finger of a user is in contact with a touchsurface;

FIG. 4A and FIG. 4B are figures depicting distributions of signal levelsin a state in which a foreign object is on the touch surface andadditionally a finger is not in contact with the foreign object(ungrounded state);

FIG. 5A and FIG. 5B are figures depicting distributions of signal levelsin a state in which a foreign object is on the touch surface andadditionally a finger is in contact with the foreign object (groundedstate);

FIG. 6 is a flowchart of a position detection method performed by theposition detection circuit in FIG. 1;

FIG. 7A is a figure depicting an exemplary foreign object recognitionprocess at S2, and FIG. 7B is a figure depicting one example of aforeign object recognition result;

FIG. 8 is a detailed flowchart of a touch detection process in a coinmode to be executed at S5 in FIG. 6;

FIG. 9 is a schematic diagram depicting an effect of improving fingerdetermination following a change of threshold (T1→T2);

FIG. 10 is a schematic diagram depicting an effect of improving singleobject determination following a change of threshold (L1→L2); and

FIG. 11 is a schematic diagram depicting an effect of improving palmdetermination following a change of threshold (S1→S2).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A position detection circuit and position detection method according tothe present disclosure are explained with reference to the attachedfigures. It should be noted that the present disclosure is not limitedto the following embodiments and variants, but can certainly be changedat will as long as such changes do not deviate from the main points ofthe present disclosure. Alternatively, individual configurations can becombined as desired as long as such combinations do not cause technicalcontradictions.

[Configuration of Electronic Device 10] <Overall Configuration>

FIG. 1 is a schematic block diagram of an electronic device 10 intowhich a position detection circuit 18 according to one embodiment of thepresent disclosure is incorporated. The electronic device 10 isconfigured as a tablet terminal, a smartphone or a personal computer,for example. A user holds an electronic pen 12 (or a stylus) with one ofhis/her hands, and moves it while pressing its pen point against a touchsurface 24 (please see FIG. 2A or other figures) of a display panelwhich is not illustrated to thereby be able to draw pictures or writecharacters in the electronic device 10. Alternatively, the user bringshis/her finger 14 of into contact with the touch surface 24 to therebybe able to perform desired manipulation through a user control beingdisplayed.

This electronic device 10 includes and constituted by a capacitive touchsensor 16, the position detection circuit 18 and a host processor 20. Itshould be noted that the x direction and y direction depicted in thefigure correspond to the X axis and Y axis of an orthogonal coordinatesystem defined on a plane formed by the touch sensor 16.

The touch sensor 16 includes and is constituted by a plurality ofelectrodes arranged on the display panel. The touch sensor 16 includes aplurality of line electrodes 16 x for detecting X coordinates (positionsin the x direction), and a plurality of line electrodes 16 y fordetecting Y coordinates (positions in the y direction). The plurality ofline electrodes 16 x is provided to extend in the y direction andadditionally is arranged at constant intervals along the x direction.The plurality of line electrodes 16 y is provided to extend in the xdirection and additionally is arranged at constant intervals along the ydirection.

The position detection circuit 18 is an integrated circuit, for example,including at least one processor device 22 configured to executeprocessor-readable instructions stored in at least one memory device 24,and is connected to each among the plurality of electrodes constitutingthe touch sensor 16. The instructions are configured to be able torealize a touch detection function of a detecting touch of the finger 14or the like of the user and a pen detection function of detecting astate of the electronic pen 12.

The touch detection function, for example, includes a function oftwo-dimensionally scanning the touch sensor 16, a function of acquiringtwo-dimensional data 30 on the touch sensor 16 (FIG. 7B), and a functionof classifying areas in the two-dimensional data 30 (for example,classification of the finger 14 and the palm of a hand). The pendetection function, for example, includes a function oftwo-dimensionally scanning the touch sensor 16, a function of receivingand analyzing downlink signals, a function of estimating the state ofthe electronic pen 12 (for example, the position, posture and penpressure), and a function of generating and sending uplink signalsincluding commands on the electronic pen 12.

The host processor 20 is a processor consisting of a Central ProcessingUnit (CPU) or a Graphics Processing Unit (GPU). The host processor 20reads out and executes a program from a program which is not illustratedto thereby, for example, perform a process of generating digital inksusing data from the position detection circuit 18, a visualizationprocess for displaying drawing contents indicated by the digital inks,and so on.

<Functional Requirements of Position Detection Circuit 18>

FIG. 2A and FIG. 2B are schematic diagrams depicting functionalrequirements about the position detection circuit 18 in FIG. 1.

As depicted on the left half of FIG. 2A, an electrically conductiveforeign object C1 such as a coin or a water drop is located on the touchsurface 24 of the electronic device 10. If the electronic device 10 istilted in this state, the foreign object C1 slides down the touchsurface 24 due to its own weight. As a first functional requirement,even if the foreign object C1 moves on the touch surface 24 while at thesame time being in contact with the touch surface 24 as depicted on theright half of FIG. 2A, it is not be detected as a series of touchmanipulation.

As depicted on the left half of FIG. 2B, there are two foreign objectsC1 and C2 located on the touch surface 24 of the electronic device 10,and additionally the user is pressing the foreign objects C1 and C2 withhis/her fingers 14. By moving the fingers 14 in this state, the foreignobjects C1 and C2 move following the motion of the finger 14. As asecond functional requirement, even if the foreign objects C1 and C2 areinterposed as depicted on the right half of FIG. 2B, the motion of thefinger 14 is detected as a series of touch manipulation.

[Operation of Position Detection Circuit 18] <Tendency of Detection ofCapacitance>

The position detection circuit 18 in the present embodiment has theabove-mentioned configuration. Next, the tendency of detection ofcapacitance by the touch sensor 16 under various use conditions isexplained with reference to FIG. 3A to FIG. 5B.

FIG. 3A is a figure depicting a one-dimensional distribution of signallevels in a state in which the finger 14 of the user is in contact withthe touch surface 24. The horizontal axis of the graph indicatespositions (Position) along one axis direction, and the vertical axis ofthe graph indicates signal levels (Level). The signal levels correspondto detection values regarding capacitance (mutual capacitance or selfcapacitance), and are set to have plus or minus signs such that theybecome “positive” when the finger 14 is in contact.

FIG. 3B is a figure depicting a two-dimensional distribution of signallevels in the state in which the finger 14 of the user is in contactwith the touch surface 24. The value of each cell indicates a signallevel at each two-dimensional position. For convenience of illustration,cells with signal levels close to a reference value (=0) are depictedwith numbers being omitted therefrom. It should be noted that a singlecell or a group of cells surrounded by a bold line frameindicates/indicate a position where a positive signal level Pv isdetected.

As can be understood from FIG. 3A and FIG. 3B, signal levels farexceeding a threshold T1 are detected in a small range corresponding toa contact portion of the finger 14 along with contact of the finger 14.

FIG. 4A and FIG. 4B are figures depicting distributions of signal levelsin the state where the foreign object C1 is on the touch surface 24 andadditionally the finger 14 is not in contact with the foreign object C1(ungrounded state). In more detail, FIG. 4A depicts a one-dimensionaldistribution, and FIG. 4B depicts a two-dimensional distribution. As canbe understood from FIG. 4A and FIG. 4B, not only small areas withpositive signal levels Pv but also small areas with signal levels Nvwith negative values are mixedly present in the area where the foreignobject C1 is present.

FIG. 5A and FIG. 5B are figures depicting distributions of signal levelsin a state in which the foreign object C1 is on the touch surface 24 andadditionally the finger 14 is in contact with the foreign object C1(grounded state). In more detail, FIG. 5A depicts a one-dimensionaldistribution, and FIG. 5B depicts a two-dimensional distribution.

Along with contact of the finger 14, negative signal levels Nvdisappear, and relatively low positive signal levels Pv start beingdetected in a large range corresponding to the contact portion of theforeign object C1. A reason for this is assumed to be that although theamount of electric charges Q absorbed from the finger 14 does not changemuch irrespective of the presence or absence of the foreign object C1,the contact area of the foreign object C1 is larger than the contactarea of the finger 14, and the amount of absorption of electric chargesper unit size decreases.

<Specific Operation>

In view of the detection tendency explained above, the two functionalrequirements (please see FIG. 2A and FIG. 2B) can be realizedsimultaneously. In the following, specific operation of the positiondetection circuit 18 is explained with reference to the flowchart inFIG. 6. It should be noted that this operation may be performed by oneprocessor (position detection circuit 18) or may be performed by aplurality of processors in cooperation with each other.

At S1 in FIG. 6, the position detection circuit 18 receive input ofdetection signals indicating detection values regarding capacitance onthe touch sensor 16, and acquires distribution data indicating aposition distribution of detection levels (hereinafter, referred to alsoas the two-dimensional data 30).

At S2, the position detection circuit 18 recognizes the electricallyconductive foreign object C1 located above the touch sensor 16 (that is,the foreign object C1 in contact with the touch surface 24) based on thetwo-dimensional data 30 acquired at S1.

FIG. 7A is a figure depicting an exemplary foreign object recognitionprocess at S2. In this process, a pattern larger than the contact rangeof the finger 14 (hereinafter, referred to also as a coin pattern) isrecognized, and the coin pattern is extracted as a recognition area 32.As explained above, such a coin pattern does not generate an area whereareas with positive signal levels Pv and areas with negative signallevels Nv are distinctly separated, but actually generates an area wheresmall areas of the two types are mixedly present. The portions that arepainted out correspond to small areas where positive signal levels Pv(1)and Pv(2) are detected, and the hatched portion corresponds to smallareas where negative signal levels Nv are detected. Accordingly, when acoin pattern is to be recognized, recognition conditions desirablyinclude that signal levels with different signs are mixedly present,instead of detecting the boundary (edges) between areas.

In addition to this, or instead of this, a recognition condition aboutthe size of the recognition area 32 may be included. Specifically, anarea having a size larger than predetermined size CS may be extracted asthe recognition area 32. A reason for this is that the above-mentionedproblems in terms of manipulation of the electronic device 10 cannotoccur in an area that is sufficiently smaller than a water drop, a coinor the like. It should be noted that the size of an area can be obtainedfor example based on the number of data points at which the absolutevalues of signal levels are above a threshold and that are adjoiningeach other to form a cluster.

FIG. 7B is a figure depicting an exemplary result of recognizing theforeign object C1. The two-dimensional data 30 is defined in apredetermined entire rectangular area (0≤X≤Xo, 0≤Y≤Yo). The closed areaindicated by hatching corresponds to the recognition area 32 of theforeign object C1. In addition, the area surrounded by a broken linecorresponds to the recognition area 32 itself or a foreign objectpresent area 34 further including surrounding portions of therecognition area 32 (an area where the foreign object C1 is present). Onthe other hand, the remaining area of the entire area excluding theforeign object present area 34 corresponds to a normal detection area 36where the foreign object C1 is not present.

If at S3 in FIG. 6, the foreign object C1 (coin pattern) is notrecognized in the two-dimensional data 30 (S3; NO), the positiondetection circuit 18 performs a touch detection process in a normal mode(S4). In this normal mode, touch positions or touch areas are detectedin the entire area of the touch sensor 16 based on normal touchdetermination conditions. Specifically, [A] finger determination ofdetermining whether or not the finger 14 is in contact with the touchsurface 24, [B] single object determination of determining whetheradjoining touch areas correspond to contact of a single continuum(so-called single touch) or to simultaneous contact of separatecontinuums (so-called multi touch), and [C] palm determination ofdetermining whether or not a palm is in contact with the touch surface24 are performed.

In the “finger determination,” touch areas where detection valuesindicated by the two-dimensional data 30 are higher than the thresholdT1 (detection threshold) are extracted, and a representative point (forexample, the centroid position) of the touch areas is detected as aposition indicated by the finger 14. In the “single objectdetermination,” if touch areas where detection values indicated by thetwo-dimensional data 30 are higher than the threshold T1 are extracted,and an index indicating a change amount of detection values betweenadjoining touch areas is lower than a threshold L1 (change amountthreshold), both the touch areas are regarded and detected as a singlearea. In the “palm determination,” if touch areas where detection valuesindicated by the two-dimensional data 30 are higher than the thresholdT1 are extracted, and an index indicating the size of the touch areas ishigher than a threshold S1 (size threshold), the touch areas are deemednot as corresponding to an indication intended by the user, and areexcluded from touch areas.

On the other hand, returning to S3, if at least one foreign object C1 isrecognized in the two-dimensional data 30 (S3; YES), the positiondetection circuit 18 performs a touch detection process in a coin mode(S5). In this coin mode, a process of detecting touch positions or touchareas in the two-dimensional data 30 is performed using different touchdetermination conditions for the outside and inside of the foreignobject present area 34.

Here, the “different touch determination conditions” may include: [1]that parameters (for example, thresholds) used in determinationprocesses are different; [2] that methods of calculating indices used indetermination processes are different; [3] combinations/the number ofconditions among a plurality of determination conditions are different;and [4] combinations of [1] to [3] explained above. In the following, anexemplary touch detection process in the coin mode performed at S5 isexplained in detail with reference to a flowchart in FIG. 8 and FIG. 9to FIG. 11.

First, at S51 in FIG. 8, the position detection circuit 18 performs the“finger determination” using a threshold T2 lower than the threshold T1used in the normal mode. As can be understood from the relationshipsdepicted in FIG. 3A and FIG. 5A, positive signal levels Pv based onwhich contact of the finger 14 is detected tend to lower relatively dueto interposition of the foreign object C1. In view of this, in the coinmode, the threshold T2 is used instead of the threshold T1 to increasethe touch detection sensitivity. Thereby, as depicted in FIG. 9, touchof the finger 14 can be detected even if the foreign object C1 isinterposed.

Next, at S52, the position detection circuit 18 performs the “singleobject determination” using a threshold L2 higher than the threshold L1used in the normal mode. As can be understood from the relationshipsdepicted in FIG. 3A and FIG. 5A, the range over which positive signallevels Pv appear becomes larger relatively due to interposition of theforeign object C1, and the tendency of easily detecting discontinuity isfacilitated by a corresponding degree. In view of this, in the coinmode, the threshold L2 is used instead of the threshold L1 to lower thediscontinuity detection sensitivity. Thereby, as depicted in FIG. 10,the foreign object C1 can be detected as a single object even in a statein which the finger 14 is in contact with the foreign object C1.

Next, at S53, the position detection circuit 18 performs the “palmdetermination” using a threshold S2 higher than the threshold S1 used inthe normal mode. For example, since if a coin pattern is detected in thepalm determination, the coin pattern is excluded from a touch area,touch manipulation by the finger 14 is more easily invalidated. Inparticular, such influence becomes more significant in cases where theforeign object C1 is highly fluid (for example, a water drop, etc.). Inview of this, in the coin mode, the threshold S2 is used instead of thethreshold S1 to lower the palm area detection sensitivity. Thereby, asdepicted in FIG. 11, invalidation of touch manipulation by the finger 14is suppressed even if the foreign object C1 is interposed.

Last, at S54, the position detection circuit 18 outputs touch positions(coordinate values) in the foreign object present area 34 according toresults of determination at S51 to S53.

[Effects of Position Detection Circuit 18]

In the above-mentioned manner, the position detection circuit 18 is acircuit connected to the capacitive touch sensor 16 formed with aplurality of line electrodes 16 x, 16 y that are two-dimensionallyarranged, in which the position detection circuit 18 performs: acquiringthe two-dimensional data 30 indicating a distribution of detectionvalues regarding capacitance on the touch sensor 16 (S1); recognizingthe electrically conductive foreign objects C1 and C2 located above thetouch sensor 16 based on the acquired two-dimensional data 30 (S2); anddetecting a touch position or touch area on the touch sensor 16 based onthe two-dimensional data 30 using different touch detection conditionsfor the outside and inside of the foreign object present area 34 wherethe recognized foreign objects C1 and C2 are present (S4, S5).

Because of such a configuration, more flexible position detection can beperformed even if the foreign objects C1 and C2 are present above thetouch sensor 16 (on the touch surface 24). For example, by setting touchdetection conditions that are each appropriate for the foreign objectpresent area 34 and the normal detection area 36, position detection isperformed equally without being aware of the presence or absence of theforeign objects C1 and C2.

In addition, with this detecting, if a touch detection condition underwhich a position or area where a detection value indicated by thetwo-dimensional data 30 is larger than a threshold (T1, T2) is detectedas a touch position or touch area is used, the threshold (T1) for theoutside of the foreign object present area 34 may be relativelyincreased, and the threshold (T2) for the inside of the foreign objectpresent area 34 may be relatively lowered. By relatively increasing thetouch detection sensitivity in the foreign object present area 34, touchfrom above the foreign objects C1 and C2 is more easily detected.

In addition, with this detecting, if a touch detection condition underwhich adjoining touch areas are detected as a single touch area if achange amount between detection values of the adjoining touch areas issmaller than a threshold (L1, L2) is used, the threshold (L1) for theoutside of the foreign object present area 34 may be relatively lowered,and the threshold (L2) for the inside of the foreign object present area34 may be relatively increased. By relatively lowering the discontinuitydetection sensitivity in the foreign object present area 34, the foreignobjects C1 and C2 are more easily detected as a single object.

In addition, with this detecting, if a touch detection condition underwhich a detected area is excluded from a touch area if the size of thedetected area is larger than a threshold (S1, S2), the threshold (S1)for the outside of the foreign object present area 34 may be relativelylowered, and the threshold (S2) for the inside of the foreign objectpresent area 34 may be relatively increased. By relatively lowering thesensitivity of detecting a touch area to be excluded (that is, a palmarea), invalidation of touch manipulation is more easily suppressed evenif the foreign objects C1 and C2 are interposed.

In addition, with this recognizing, the foreign objects C1 and C2 may berecognized if there is an area where positive signal levels and negativesignal levels are mixedly present in the distribution of detectionvalues indicated by the two-dimensional data 30. By considering thecapacitance detection tendency depicted in FIG. 4A and FIG. 4B, theprecision of recognizing the foreign objects C1 and C2 improves.

What is claimed is:
 1. A position detection circuit connected to acapacitive touch sensor formed with a plurality of line electrodes thatare two-dimensionally arranged, comprising: at least one processordevice; and at least one memory device storing processor-readableinstructions that, when executed by the at least one processor device,cause the position detection circuit to: recognize a pattern larger thana predetermined size on the capacitive touch sensor; acquiretwo-dimensional data of the pattern, the two-dimensional data indicatinga distribution of detection values regarding capacitance on thecapacitive touch sensor; and detect a touch position or touch area onthe capacitive touch sensor based on the two-dimensional data usingdifferent touch detection conditions for an outside and an inside of thepattern.
 2. The position detection circuit according to claim 1, whereinthe instructions, when executed by the at least one processor device,cause the position detection circuit to: use a touch detection conditionunder which the touch position or the touch area is detected as aposition or area where a detection value indicated by thetwo-dimensional data is larger than a threshold, and under which thethreshold for the outside of the pattern is relatively increased, andthe threshold for the inside of the pattern is relatively lowered. 3.The position detection circuit according to claim 1, wherein theinstructions, when executed by the at least one processor device, causethe position detection circuit to: use a touch detection condition underwhich adjoining touch areas are detected as a single touch area if achange amount between detection values of the adjoining touch areas issmaller than a threshold, and under which the threshold for the outsideof the pattern is relatively lowered, and the threshold for the insideof the pattern is relatively increased.
 4. The position detectioncircuit according to claim 1, wherein the instructions, when executed bythe at least one processor device, cause the position detection circuitto: use a touch detection condition under which a detected area isexcluded from the touch area when a size of the detected area is largerthan a threshold, and under which the threshold for the outside of thepattern is relatively lowered, and the threshold for the inside of thepattern is relatively increased.
 5. The position detection circuitaccording to claim 1, wherein the instructions, when executed by the atleast one processor device, cause the position detection circuit to:recognize the pattern if there is an area where a positive signal leveland a negative signal level are mixedly present in the distribution ofthe detection values.
 6. A position detection method using a capacitivetouch sensor formed with a plurality of line electrodes that aretwo-dimensionally arranged, wherein the method is performed by one ormore processors and comprises: recognizing a pattern having a sizelarger than a predetermined size on the capacitive touch sensor;acquiring two-dimensional data of the pattern, the two-dimensional dataindicating a distribution of detection values of capacitance on thecapacitive touch sensor; and detecting a touch position or touch area onthe capacitive touch sensor based on the two-dimensional data usingdifferent touch detection conditions for an outside and an inside of thepattern.
 7. The position detection method according to claim 6, whereinthe detecting includes: using a touch detection condition under whichthe touch position or the touch area is detected as a position or areawhere a detection value indicated by the two-dimensional data is largerthan a threshold, relatively increasing the threshold for the outside ofthe pattern, and relatively lowering the threshold for the inside of thepattern.
 8. The position detection method according to claim 6, whereinthe detecting includes: using a touch detection condition under whichadjoining touch areas are detected as a single touch area when a changeamount between detection values of the adjoining touch areas is smallerthan a threshold, relatively lowering the threshold for the outside ofthe pattern, and relatively increasing the threshold for the inside ofthe pattern.
 9. The position detection method according to claim 6,wherein the detecting includes: using a touch detection condition underwhich a detected area is excluded from the touch area when a size of thedetected area is larger than a threshold, relatively lowering thethreshold for the outside of the pattern, and relatively increasing thethreshold for the pattern.
 10. The position detection method accordingto claim 6, wherein the recognizing includes: recognizing the pattern ifthere is an area where a positive signal level and a negative signallevel are mixedly present in the distribution of the detection values.11. An electronic device, comprising: a capacitive touch sensor formedwith a plurality of line electrodes that are two-dimensionally arranged;and a position detection circuit connected to the capacitive touchsensor, wherein the position detection circuit includes at least oneprocessor device, and at least one memory device storingprocessor-readable instructions that, when executed by the at least oneprocessor device, cause the position detection circuit to: recognize apattern having a size larger than a predetermined size on the capacitivetouch sensor; acquire two-dimensional data of the pattern, thetwo-dimensional data indicating a distribution of detection valuesregarding capacitance on the capacitive touch sensor; and detect a touchposition or touch area on the capacitive touch sensor based on thetwo-dimensional data using different touch detection conditions for anoutside and an inside of the pattern.
 12. The electronic deviceaccording to claim 11, wherein the instructions, when executed by the atleast one processor device, cause the position detection circuit to: usea touch detection condition under which the touch position or the toucharea is detected as a position or area where a detection value indicatedby the two-dimensional data is larger than a threshold, and under whichthe threshold for the outside of the pattern is relatively increased,and relatively lower the threshold for the inside of the pattern isrelatively lowered.
 13. The electronic device according to claim 11,wherein the instructions, when executed by the at least one processordevice, cause the position detection circuit to: use a touch detectioncondition under which adjoining touch areas are detected as a singletouch area if a change amount between detection values of the adjoiningtouch areas is smaller than a threshold, and under which the thresholdfor the outside of the pattern is relatively lowered, and the thresholdfor the inside of the pattern is relatively increased.
 14. Theelectronic device according to claim 11, wherein the instructions, whenexecuted by the at least one processor device, cause the positiondetection circuit to: use a touch detection condition under which adetected area is excluded from the touch area when a size of thedetected area is larger than a threshold, and under which the thresholdfor the outside of the pattern is relatively lowered, and the thresholdfor the inside of the pattern is relatively increased.
 15. Theelectronic device according to claim 11, wherein the instructions, whenexecuted by the at least one processor device, cause the positiondetection circuit to: recognize the pattern if there is an area where apositive signal level and a negative signal level are mixedly present inthe distribution of the detection values.